Systemic responses to severe trauma include a number of parameters affecting innate immunity, inflammatory reactions and cellular activities. Severe trauma patients may have a benign outcome with no infection while others suffer from infections or sepsis. Sepsis is associated with multiple organ failure and a high mortality. Among the most commonly used markers for diagnosis of sepsis are leukocyte counts, C-reactive protein and procalcitonin. The latter are two proteins highly induced after trauma, yet without any known function. In addition, cytokines such as IL-6, IL-8 and IL-18 are employed to monitor patients. However, none of the above mentioned markers serves as a predictive indicator for infections including sepsis, hence treatment may lag behind the onset of sepsis.
In animal pilot experiments, it has been shown that a pancreatic protein is induced due to handling stress, even in the absence of pancreatic tissue damage (R. Graf et al., J Surg Res 2002, 195:136-144). This protein, pancreatic stone protein/regenerating protein (PSP/reg) belongs to a family of lectin binding proteins. Under conditions of acute or chronic pancreatitis, it is highly up-regulated and may appear in the serum. Since the regulation of this protein is not purely restricted to diet induced secretion like other zymogens, it may appear elevated in other conditions, e.g. during pancreatitis. Thus far, the protein has been studied predominantly in the pancreas. It is also synthesized in PANETH cells of the small intestine and the fundic cells of the stomach. The function of PSP/reg is still highly debated, but it is generally assumed that it is involved in promoting cell proliferation during regenerative processes (Y. Kinoshita et al., J. Gastroenterol 2004, 39:507-513).
Several efforts have been made to establish PSP/reg as a disease marker. So far, it has not been possible to establish a correlation of serum values with a specific disease entity since serum levels are raised in various gastrointestinal diseases Y (Satomura et al., J Gastroenterol 1995, 30:643-650).